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A sedimentological and stratigraphical study of Veiki moraine in northernmost Sweden

Sigfúsdóttir, Þorbjörg LU (2013) In Dissertations in Geology at Lund University GEOR02 20131
Department of Geology
Abstract
Veiki moraine is a landform area consisting of rim-ridged subcircular hummocks and plateaus with depressions in between, mostly located within a N-S extending zone of a hummocky landscape. It is believed to have formed during the pre-late Weichselian and survived overriding by ice during the subsequent glaciations. Due to their good preservation, the Veiki moraine provides valuable information on the glaciation and prevailing environmental conditions in northern Sweden during the earlier stages of Weichselian glaciations, as well as the ice dynamics of the late Weichselian ice sheet.

To determine the internal stratigraphy of the moraine plateaus and interpret the depositional environment, excavation into two Veiki moraine plateaus were... (More)
Veiki moraine is a landform area consisting of rim-ridged subcircular hummocks and plateaus with depressions in between, mostly located within a N-S extending zone of a hummocky landscape. It is believed to have formed during the pre-late Weichselian and survived overriding by ice during the subsequent glaciations. Due to their good preservation, the Veiki moraine provides valuable information on the glaciation and prevailing environmental conditions in northern Sweden during the earlier stages of Weichselian glaciations, as well as the ice dynamics of the late Weichselian ice sheet.

To determine the internal stratigraphy of the moraine plateaus and interpret the depositional environment, excavation into two Veiki moraine plateaus were carried out. The sections investigated were supplemented by morphological data from LiDAR elevation models and GPR profiles. In addition, sorted sediment units within the two Veiki moraine plateaus were sampled for radiocarbon and OSL dating.

The two moraine plateaus investigated seem to consist of massive diamicton in the center. The rim ridges are built up by stratified debris flow units, partly underlain by organic-rich lake sediment. The elevated position of these sediments indicates that the moraines were surrounded by ice at the time of deposition. They are interpreted to have formed by debris and meltwater inflow into depressions on a debris-covered stagnant ice mass. After the surrounding ice had melted they were left standing as high points in the landscape. The moraine plateaus and the surroundings are covered by a thin till bed deposited by subsequent glaciations. Dating of lake sediment suggest deposition around 50,000 years BP. This indicates deposition during the Tärandö II interstadial, which followed the glaciation in MIS 4 during the Weichselian glaciation cycle. (Less)
Abstract (Swedish)
Veikimoräner är cirkulära moräner med ryggar längs kanterna som kan hittas i norra Sverige. Majoriteten är belägna längs en N-S gående kuperat landskap. Moränerna tros ha bildats under tidig-mellan Weichsel och har överlagrats av glaciärer från efterföljande glaciationer. Tack vare att Veikimoränerna har bevaratas i så gott skick kan dessa moräner ge värdefull information om glaciationer och dåvarande miljömässiga förrhållande under glaciationen i norra Sverige under tidig Weichsel samt inlandsisens dynamik under sen Weichsel.

För att bestämma den invändiga stratigrafin av moränerna samt tolka avsättningsmiljön gjordes utgrävning av två Veiki moräner. Sektionerna undersöktes och kompletterades med morfologisk data från LiDAR... (More)
Veikimoräner är cirkulära moräner med ryggar längs kanterna som kan hittas i norra Sverige. Majoriteten är belägna längs en N-S gående kuperat landskap. Moränerna tros ha bildats under tidig-mellan Weichsel och har överlagrats av glaciärer från efterföljande glaciationer. Tack vare att Veikimoränerna har bevaratas i så gott skick kan dessa moräner ge värdefull information om glaciationer och dåvarande miljömässiga förrhållande under glaciationen i norra Sverige under tidig Weichsel samt inlandsisens dynamik under sen Weichsel.

För att bestämma den invändiga stratigrafin av moränerna samt tolka avsättningsmiljön gjordes utgrävning av två Veiki moräner. Sektionerna undersöktes och kompletterades med morfologisk data från LiDAR höjdmodeller och GPR profiler. Sorterade sedimentenheter i de två Veikimoränerna provtogs för 14C och OSL datering.

De undersökta moränerna verkar bestå av massiva diamikton i de centrala delarna. Ryggkanterna är uppbyggda av stratifierade massflöden delvis underlagrade av sjösediment rika på organiskt material. Den upphöjda positionen av dessa sediment indikerar att moränerna var omgivna av is när de deponerades. De har tolkats som att de bildats när glaciärmaterial och smältvatten har runnit in i en depression som legat på en glaciärmaterialtäckt stagnant is. När omgivande is smälte bort blev dessa landformer kvar som höga områden i landskapet. Moränerna och omgivande område är överlagrat av ett tunt lager av morän som deponerats av de efterföljande glaciationerna. Dateringar av sjösedimenten tyder på deposition vid 50.000 BP vilket korrelerar till Tärandö II inderstadialen. Denna interstadial kom efter MIS 4, under Weichsel. (Less)
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author
Sigfúsdóttir, Þorbjörg LU
supervisor
organization
alternative title
En sedimentologisk och stratigrafisk Veikimoränstudie från norra Sverige
course
GEOR02 20131
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Veiki moraine, glacial geology, Weichselian glaciation, northern Sweden, supraglacial lakes, Veikimorän, glacialgeologi, Weichselistiden, norra Sverige, supraglacial sjö
publication/series
Dissertations in Geology at Lund University
report number
354
language
English
id
3911959
date added to LUP
2013-07-02 20:57:10
date last changed
2013-07-02 20:57:10
@misc{3911959,
  abstract     = {Veiki moraine is a landform area consisting of rim-ridged subcircular hummocks and plateaus with depressions in between, mostly located within a N-S extending zone of a hummocky landscape. It is believed to have formed during the pre-late Weichselian and survived overriding by ice during the subsequent glaciations. Due to their good preservation, the Veiki moraine provides valuable information on the glaciation and prevailing environmental conditions in northern Sweden during the earlier stages of Weichselian glaciations, as well as the ice dynamics of the late Weichselian ice sheet.
	
To determine the internal stratigraphy of the moraine plateaus and interpret the depositional environment, excavation into two Veiki moraine plateaus were carried out. The sections investigated were supplemented by morphological data from LiDAR elevation models and GPR profiles. In addition, sorted sediment units within the two Veiki moraine plateaus were sampled for radiocarbon and OSL dating.
	
The two moraine plateaus investigated seem to consist of massive diamicton in the center. The rim ridges are built up by stratified debris flow units, partly underlain by organic-rich lake sediment. The elevated position of these sediments indicates that the moraines were surrounded by ice at the time of deposition. They are interpreted to have formed by debris and meltwater inflow into depressions on a debris-covered stagnant ice mass. After the surrounding ice had melted they were left standing as high points in the landscape. The moraine plateaus and the surroundings are covered by a thin till bed deposited by subsequent glaciations. Dating of lake sediment suggest deposition around 50,000 years BP. This indicates deposition during the Tärandö II interstadial, which followed the glaciation in MIS 4 during the Weichselian glaciation cycle.},
  author       = {Sigfúsdóttir, Þorbjörg},
  keyword      = {Veiki moraine,glacial geology,Weichselian glaciation,northern Sweden,supraglacial lakes,Veikimorän,glacialgeologi,Weichselistiden,norra Sverige,supraglacial sjö},
  language     = {eng},
  note         = {Student Paper},
  series       = {Dissertations in Geology at Lund University},
  title        = {A sedimentological and stratigraphical study of Veiki moraine in northernmost Sweden},
  year         = {2013},
}